Generally, an electric apparatus is driven by electric power supplied from a power supply. An electric apparatus typically receives electric power via a connector from a power supply. Patent documents 1 and 2 disclose a connector unit including a protruding male connector and a hollow female connector that are fitted together to be electrically connected.
In recent years, as a measure to cope with global warming, it is being considered to use, even for power transmission in local areas, a direct-current high-voltage power that suffers less power loss during voltage conversion and power transmission and does not necessitate increasing the diameter of a cable. Supplying electric power in this manner is particularly preferable for an information apparatus such as a server that consumes a large amount of electric power.
On the other hand, when electric power supplied to an electric apparatus has a high voltage, the electric power may affect the human body and operations of electronic components. When such a high-voltage power is used for an information apparatus such as a server that is installed and maintained by a human, it is necessary to use, for electric connection, a connector that is different from a connector used for a normal alternating-current commercial power supply.